Standards of Measurement

Chapter 1 Section 2

Learning Targets• Students will understand the difference between

English and SI measuring systems.• Students will learn about the common prefixes for

SI measuring system and the SI base units.• Students will start to learn how we will convert to

alternative units in science using math.

Systems of Measurement

• What system do we use in the United States?

• The English System• What are some familiar English

measurements that we use?• Inches, feet, yards, miles, ounces,

acre’s

Systems of Measurement

• Almost all the rest of the world uses the International System of units, or the SI system.

• This system is based on multiples of 10, which makes math easier.

• Prefixes are used to indicate what multiple of ten should be used with the units.

• For Example, the prefix kilo- means “1,000”• We use SI for consistency in research, and

gathering information.

Common SI PrefixesPrefix Symbol Multiplying

FactorsKilo- k 1,000

Deci- d 0.1

Centi c 0.01

Milli- m 0.001

Micro- µ 0.000 001

Nano- n 0.000 000 001

SI Base UnitsQuantity Measured Unit Symbol

Length Meter m

Mass Kilogram kg

Time Second s

Electric Current Ampere A

Temperature Kelvin K

Amount of substance Mole mol

Intensity of Light Candela cd

The United States is weird!

• The United States is 1 out of only 5 countries in the world that does not use the SI System.\

• Why do we not use the SI system?• So if we wanted to switch from feet to inches,

how do we do that?• Math is the language of science!• We will now practice switching measurements

using the English system first, and then we will latter try switching with the SI system!